Fuze



Marchfi, 1-956 M. COOPER Original Filed Nov. 7, 1944 BY 2 E ATTORNEYINVENTOR. Lyle M. Cooper United States FUZE Lyle M. Cooper, Rahway, N.J., assignor to the United gt ates of America as represented by theSecretary of Original application November 7, 1944, Seriai No. 562,370,now Patent No. 2,666,389, dated January 19, 1954. Divided and thisapplication June 10, 1953, Serial No. 360,734

3 Claims. (Cl. 102-73) This application is a divisional application ofmy copending patent application Serial No. 562,370, filed November 7,1944, entitled Fuze, now Patent 2,666,389, granted January 19, 1954.

This invention relates to a combination percussion and time fuze orfiring mechanism particularly adapted for use in tail ejection typebombs released from aircraft in clusters.

Tail ejection incendiary bombs were given greater capabilities andbecame standardized when equipped with fuzes made in accordance with thepresent invention. The bombs are made up of two principal assemblies,the fuze and the case. The case serves as a container for an incendiaryor chemical agent, an ejection charge, and the fuze. The fuze fittedinto the case is the means for transforming energy of impact into acontrolled ignition for firing the ejection charge.

An object of the invention is to provide a fuze sufiiciently compact toincrease the loading etficiency of the bomb, simple for safe handling,easy assembly and man facture with a minimum of scarce materials, sealedfor waterproofness, and constructed for dependable functioning even whenthe bomb slants at an angle from the vertical on impact with surfaces ofvarious degrees of hardness.

It is a specific object of this invention to provide an allways fuzewhich is responsive to impact regardless of the angle of impact made bythe bomb with regard to the target, thereby being particularly suitablefor incendiary bombs, grenades and the like.

The above and other objects of the invention will become apparent fromthe accompanying drawings, where- Fig. 1 is a side view of the all-waysfuze unit with a part broken away and its safety plunger in its armedposition.

Fig. 2 is a longitudinal, cross-sectional view of the allways fuseillustrated in Fig. 1, rotated through an angle of 90 about itslongitudinal axis, and with its safety plunger in its unarmed position.

Fig. 3 is a cross sectional view taken on line 3-3 in Fig. 1.

Fig. 4 is a longitudinal cross section of the safety assembly.

Referring to the drawings, my improved, all-ways fuze comprises a casing1 which is made of brass, steel tubing or similar tough metal, whichhouses base 2 in one end thereof. Base 2 is provided with a pair ofaxially inwardly extending projections 13 on each lateral side thereof(see particularly Fig. 3), and two primer caps 9 mounted in its inwardlyfacing side. Projections 13 have aligned hinge pin bores 14 formedtherein which are adapted to receive hinge pins 15. Two L-shaped strikerlevers are pivoted at their corners on hinge pins 15. Each of theL-shaped levers has a short arm 17 carrying a firing pin 20, and eachhas a longer arm 18 which is bent at its end opposite to the one havingshort arm 1'7. The L-shaped striker levers are disposed generally in2,737,117 Patented Mar. 6, 1956 parallel positions. Any rotationalmovement of the bent ends of the longer arms 18 towards the center ofthe fuze serves to drive the firing pin 20 of the integrally moved shortarm 17 into a primer cap 9 fixed in the fuze base 2, causing firing ofthe primer. Movement of either of the longer arms 18 toward the centerof the fuze is opposed by a spring 21 which tends to keep the longerarms 18 in a position substantially perpendicular to the inwardly facingside of the base 2 and parallel to the long axis of the fuze. The longerarms 18 are linked at about their mid-points by a taut but flexible wireor chain 31 to a relatively heavy weight 32. Movement of this weight 32in any direction tends to move one or both of the long arms 18 towardthe center of the fuse with sufficient force to overcome the restraintof spring 21, thereby rotating either or both striker levers on theirpivots at hinges 15 so that the firing pins 20 on the short striker arms17 are forced in the direction of their underlying primer caps 9. When amunition carrying the fuze receives adequate impact, the momentum orinertia of the weight 32 forces it from its normal position and one orboth caps 9 are fired through the rotational movement of one or both ofthe striker levers with the restraining pressure of spring 21 overcome.

The primer caps 9 are mounted in primer cap wells formed in the inwardlydirected face of the base 2, and are aligned with the firing pins 20.The primer cap wells and a vent-hole 16 lead into an adjoining chamber,at the opposite end of which there is a central bore in externallythreaded plug 10 containing a pressed powder core 11 formed of amaterial which is ignited when either one or both primers 9 are firedand then burns in an approximately determined time delay period of aboutone or a few seconds. At the final burning end of this delay element,the base 2 has an attached plastic cup 12 filled with a booster or firstfire charge of black powder. This booster charge can detonate the maincharge in a bomb, grenade, or other munition in which the fuze is used.

The all-ways fuze may be provided with a simple safety means which iscapable of keeping the fuze unarmed in a cluster. The safety plungerassembly 7 is mounted in a recess 6 formed in a head which is mounted inthe casing 1 at the end opposite to the one in which the base 2 ismounted. It should be noted in this connection that conventionalsecuring means 33 are used to secure both the base and the head inposition in the casing 1. The safety plunger assembly 7 is of the typewhich has been used in standardized incendiary bombs but somemodification has been made to adapt it to applicants fuze because of therelatively small distance that the striker levers travel. The safetyplunger assembly 7 includes a plunger pin 26 that has a button end 28projecting out of the head and a disk 34 secured to its inner end. Thissafety mechanism is of the same design as that of Fig. 4 of Patent2,266,389 except for the attachment of disk 34. It comprises athin-walled sleeve 24 made'of brass, sliding metal or the like, housinga coiled spring 25 under compression and the stem 26 of the plunger pin.The plunger pin has a flange 27 which bears against one end of spring25. A thin washer 30, fitted closely around stem 26 between thecompression spring and the inner end of the brass sleeve 24, enablesbetter control of the plunger movements. The plunger pin 26, which isnormally spring pressed to its armed position (shown in Fig. 1), may beforced to its unarmed position shown in Fig. 2, wherein the disk 34 islocated between the inwardly-directed, bent ends of the long arms 18 ofthe striker levers, thereby preventing motion of the striker levers andmaintaining the fuze unarmed. When the bombs are released from thecluster and dispersed, plunger rod 26 is urged to its armed positionwherein the disk 34 no longer prohibits movement of the striker levers.Threads 29 are provided on the exterior of the head to facilitatemounting of a fuze in a munition.

Upon impact of the bomb or projectile having the described all-ways fuzeon the target, the suspended weight 32 being free to move in anydirection, continues to move in the general direction of flight whilethe munition is decelerated by impact. Regardless of the direction ofthe motion, resulting force components pull one or both of the long arms18 of the striker levers towards the fuze center-line. This motion ofone or both of the striker levers causes one or both the primers 9 to befired, which in turn ignites the pressed powder core 11 of the delayelement, then following the period of delay ignites the booster chargein cup 12. The fuze may be made to operate instantaneously without delayby merely omitting the powder delay element or substituting therefor aninstantaneous burning or detonating powder charge.

The types of primer, powder delay train, and booster charge which workwell in the fuze are standard available materials. In tested fuzes whichgave satisfactory results, new No. 4 primer caps manufactured forsmokeless powder paper shot shells by Winchester Repeating Arms Co., NewHaven, Conn., and covered by U. S. Army Specifications on Primer, newNo. 4 were used. For the delay train, a lead spitter fuze (consisting ofa black powder mixture contained in a lead tube) inch length made by theEnsign-Bickford Co., Simsbury, Conn., and known as Type D were used.Army black powder, Grade A, No. 4 was used as a first fire charge incellulose nitrate plastic cups (about 80% cellulose nitrate havingapproximately an 11% nitrogen content and plasticized about 20%camphor), the cups having a wall thickness of about 0.01 inch, a depthof about 7 inch, and made to fit snugly into a cylinder inch I. D. Itwill be understood, however, by those skilled in the art that variationsmay be made in the selection of the components, their ingredients anddimensions.

Fuze units made in accordance with this invention were subjected toextensive surveillance tests and met stringent requirements ofstandardization.

In addition to their primary attribute of being efiicient all-ways fuzessome practical advantages of the fuze units are:

(1) Safety in assembling due to the independent restraining action ofthe torsion spring even when the safety plunger does not unarrn thefuze; and

(2) Consistent cooperative action of the delay element and first firecharge with the primer in the combination unit.

It is to be noted that the fuze may be made of common materials withvery small amount of machinery. The die casting of the fuze base,preferably of aluminum base alloy, greatly simplifies the construction,and very little tooling is needed for other portions of the fuze. Eventhough under some rigorous conditions, e. g., when a bomb has a highterminal velocity and impacts on concrete at an extremely lowtemperature on the order of minus 40 F., resulting in a fracturing ofthe die cast base, this failure does not prevent functioning of thefiring mechanism since the outer casing holds the fuze componentsintact.

My all-ways fuze may be fixed in a bomb body or other type of munitionin any position for satisfactory functioning, e. g., horizontally,vertically, or at any angle and in any part of the bomb or munition.

It is to be understood that although the invention has been described indetail with respect to a preferred specific embodiment, thatmodifications come within the spirit and scope thereof.

I claim:

1. An all-ways fuze comprising an elongated casing, a base in one end ofsaid casing, two primer charges spaced apart on said base, twosubstantially rigid strikers each formed of a longer arm and a shorterarm arranged substantially at right angles to each other, said strikersbeing pivotally mounted on hinge pins in such positions that the longerarms extend at opposite sides of said casing substantially parallel tothe longitudinal axis thereof, a firing pin rigidly mounted on eachshorter arm, in alignment with and spaced a short distance from and ofsaid primer charges, spring means acting on said strikers in suchdirections as to normally hold said firing pins away from said primercharges, a weight mounted between the longer arms in such a manner as tobe capable of movement in any direction, and at least one flexiblestrand connecting said weight to said longer arms at points remote fromsaid shorter arm, whereby movement of said weight in any direction willmove at least one of said firing pins toward its corresponding primercharge.

2. A fuze as defined in claim 1 and further comprising a restrainingmember interposed between said longer arms in such a position as toprevent their movement toward each other, and resilient means for movingsaid restraining means out of engagement with said arms to thereby armsaid fuze.

3. An all-ways fuze comprising a substantially cylindrical casing, abase mounted in a first end of said casing, said base having a centralbore, a booster charge mounted in the outer end of said base incommunication with said bore, two spaced primer charges supported by theinner end of said base in communication with said bore, two hinge pinsmounted diametrically opposite each other on the inner end of said base,a substantially rigid striker pivotally mounted on each hinge pin, eachof said strikers comprising a longer arm extending along said casingfrom said hinge pin substantially parallel to the axis of said casingand a shorter arm extending across said casing from said hinge pin, afiring pin rigidly mounted on each of said shorter arms in alignmentwith and spaced a short distance from one of said primer charges, asubstantially U-shaped spring passing about said hinge pins and havingits ends engaging said longer arms in such a manner as to normally holdsaid firing pins away from said primer charges, a weight mounted betweensaid longer arms in such a manner as to be capable of movement in anydirection, at least one flexible strand joining said weight to each ofsaid longer arms at points remote from said hinge pins, the ends of saidlonger arms being bent radially inward, a head mounted in the second endof said casing, an axially movable plunger mounted in said head with itsaxis parallel to the axis of said casing, said plunger being movablefrom an outer position in which it projects outwardly beyond said headto an inner position, a spring urging said plunger toward said outerposition, and a disk on the inner end of said plunger, said plunger anddisk being so proportioned that when said plunger is in said innerposition said disk lies between said ends of said longer arms andprevents inward movement of said longer arms, and when said plunger isin said outer position, said disk clears said ends, thereby arming saidfuze.

References Cited in the file of this patent UNITED STATES PATENTS559,495 Rapieff May 5, 1896 1,234,713 Asbury July 31, 1917 1,242,053Shinkle Oct. 2, 1917

